Fan-blade.



C. P. BANZHOF.

FAN BLADE.

APPLxcAnoya FILED Aue.24. 1914.

Mmmm. 111915.

- Hearn-swf liti UNTTED sTaTns raTanT critica..

CHARLES P. BANZHOF, LANCASTER, IPENNSYLVANIA, ASSIG-NOR OF0NEFOURTH TOLEVI W. HCRTING, ONE-FOURTH T0 CHARLES F. STAUFFER, AND ONE-FOURTH TOBENJAMIN G. STAUFFER, ALL OF LANCASTER, PENNSYLVANIA.

FAN-BLADE.

.Specication' of Letters Patent. Patentgd Aug, 17, 1915.

Application led August 24, 1914. Serial N0. 858,221.

To all whom 'it may concern:

Be it known that I, CHARLES P. BANzHoF, a citizen of the United States,residing at Lancaster, in the county of Lancaster and State ofPennsylvania, have invented certain new and useful Improvements in Fan-Blades; and I hereby declare that the following is a full, clear, andexact descriptiony thereof, reference being had to the accompanyingdrawings, which form part of this specification.

This invention relates to rotary fans for use in producing a circulationof air, for ventilating and cooling rooms and other purposes, and moreparticularly to fans of the propeller type used in private residences,hotels, &c. and having paddles, blades or vanes which radiate from acommon center gles to the axis of rotation or shaft on which v the fanArevolves, thus covering much more space than is covered by fans asheretofore constructed and used for such purposes.4

The invention will first be hereinafter described, with reference to theaccompanying drawings, which form a part of this specification, and thenpointed out in the claims at the end of the description.

In said drawings, Figure 1 is a side elevation, partly in section, of arotary fan embodying my invention; Fig. 2 illustrates one of the fanblades detached, as seen from a point above, when .arranged in theposition shown in Fig.'1. 'Fig 3 is a perspective view of one of saidblades, as seen from the rear or side thereof lopposite the direction ofrotation; Fig. 4 is a longitudinal sectional view, taken on the line 4-4of F1g. 3, and Fig. 5 is a cross section, taken on the line 5 5 of Fig.1 looking in the direction of the arrow.

Referring to the drawings, in which the same reference characters areused to denote corresponding parts in dilferent views,l the letter A maydenote an ordinary electric motor adapted to be suspended from theceiling or other overhead support and havling attached to the armatureshaft of the ,motor a series 0f tubular arms B, each carrying a paddle,blade or v-ane C, constructed 1n accordance with my invention. Anydesired number of such blades may be used,

four being used in the construction shown,

The blade C is of oblong form and angular in cross section, graduallyenlarging or fiaring toward its free or outer end. For a distancepreferably about equal to one-half its length the blade is straight on amedian line and has its side portions c, 01, inclined from said medianline at an obtuse angle t0 each other, as indicated more clearly in Fig.5 of the drawings. A tang C1 is welded or otherwise secured to saidblade along said median line, being also straight the length of itsunion with said straight portion of the blade, and has its free endinclined at an obtuse angle to said straight portion in order that theblade may be arranged in said position and at the required angle toproduce the desired result. From a point preferably about midway of itslength the larger or flaring portion of the blade extends at an angle tosaid straight portion and also has its sides slightly curved or inclinedlaterally at an obtuse angle to each other, and

vsaid enlarged portion is also inclined rearwardly atan'obtuse angle tosaidcentrally disposed straight portion of the smaller half of theblade; the angle of inclination of the sides of said larger portiongradually decreasing from its junction with said smaller portion totheouter end thereof. I thus 'provide a blade which when placed in theposition shown in Fig. 1 of the drawings presents in the direction ofrotation a straight impact surface, providedy by the part c, and adownwardly and rearwardly inclined surface provided by the part c1, andan outwardly andrea'rwardly inclined surface c2 of greater extent thanthe combined surfaces of the parts c and 01,' said surface c2 graduallymerging into` a nearly fiat portion at the outer end of the blade,whereby the fan blades are adapted to collect and direct currents ofair-,from and along said surfaces downwardly, or in a direction at rightangles to the axis of rotation, and radially or outwardly, spreading andsweeping over a large area in a blast or gust of wind.

lt will be understood, of course, that the rsize of the blades may bevaried according to the requirements or wishes of the user ormanufacturer, and that their positions may be changed as desired, towhich end the shank of the blade may be adjustably seadjustment forincreasing the diameter of the circle described by the fan blades, and

ferent positions shown in full and dotted lines in Fig. 5 of thedrawings.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A fan blade of oblong form gradually enlarging or increasing in Widthtoward its free end, the sides of the inner smallerv portion thereofbeing inclined at an obtuse angle to each other from a line extendingabout midway longitudinally of the blade and the sides 'of its outerlarger portion being similarly inclined from said line; the inclinationof the sides of said outer portion gradually decreasing to the extremeouter end of the blade.

Q A fan blade of oblong form gradually enlarging or increasing in widthtoward its free end, the sides of the inner smaller portion thereofbeing inclined at an obtuse angle to each other from a line extendingabout midway longitudinally of the blade and the sides of its outerlarger .portion be` Y ing similarly inclined from said line; saidsmaller portion being Straight along said Yinclined line and having atang secured outer portion gradually decreasing to the eXtreme outer endof the blade.

3. A rotary fan comprising a plurality of I Atoward theirA outer ends,the sides of the smaller portions thereof being inclined at an obtuseangle to each other for about onehalf the length of the blade and fromthat point the sides of the larger portions being similarly inclined andsaid larger portions also inclined rearwardly, the inclination of thesides of the larger portions gradually decreasing toward the free endsof -the blades and the smaller portions thereof being straight along aline extending longitudinally of the blade about midway thereof.

4. A fan blade of the propeller type constructed 'in Aoblong formgradually increasing in width toward its outer end; the sides of itsinner smaller portion being inclined at an angle to each other andsubstantiallyiiat on their front faces, said sides mergin into thelargerouter portion, the sides o which' are similarly inclined from theirjunction with said inner portion, the latter being straight along amedian line and said `outer portion being also inclined at an ob-Y(JH-Anillas P. BANzHoF.

Witnesses:

CHAS. F. STAUFFER, M. C. StroNER.

